Here is an overview of what is to come. In Sections I and II, I will sketch two of the projects frequently pursued by moral philosophers, and the methods typically invoked in those projects. I will argue that these projects presuppose (or at least suggest) a particular sort of account of the mental representation of human value systems, since the methods make sense only if we assume a certain kind of story about how the human mind stores information about values. The burden of my argument in Section III will be that while the jury is still out, there is some evidence suggesting that this account of mental representation is mistaken. If it is mistaken, it follows that two of the central methods of moral philosophy have to be substantially modified, or perhaps abandoned, and that the goals philosophers have sought to achieve with these methods may themselves be misguided. I fear that many of my philosophical colleagues will find this a quite radical suggestion. But if anything is clear in this area, it is that the methods we will be considering have not been conspicuously successful, though it certainly has not been for want of trying. So perhaps it is time for some radical, empirically informed rethinking of goals and methods in these parts of moral philosophy.